Fuse



Jul 1, 1952 w. BRANDT FUSE 2 SHEETS-SHEET 1 Filed July 11, 1947 ImventorE. W. BRANDT July 1, 1952 FUSE 2 SHEETS-SHEET 2 Filed July 11, 1947Zhwentor @Wd (IttornegS Patented July 1, 1952 UNITE FUSE ofLiechtenstein Application July 11, 1947, Serial No. 760,424

' In Switzerland December 7, 1946 3 Claims. I

This invention relates to percussion fuzes.

The increase in the number of armoured fighting vehicles and theprogress made in connection therewith, compel the defender to employvery powerful weapons specially designed to combat such vehicles.

In this connection, hollow charge projectiles offer great possibilities.These anti-tank projectiles, which have been the subject of numerousimprovements, have increased in perforating power, speed and accuracy.It is very important to ensure their correct operation in respect ofpercussion on impact even at very high incidences, since modern tankspresent oblique sur- A faces or sloping shapes, so that the projectilesfrequently ricochet off their wall without having functioned, or burstonly after having been deflected, which reduces their perforating power.

The present invention aims at providing a hypersensitive percussionfuze, functioning either by being driven in or by inertia, providingsafety against dropping, and complying with the requirements ofutilization for high incidence firing.

The fuze of the present invention has no arming device requiring anymanipulation before firing the projectile. It is therefore of greatsimplicity of construction and may be very small, light, and so designedthat the detonating cap that it carries is sufiicient to ensure itsdestruction on impact. By reason of this fact, this fuze, which isparticularly adapted to be mounted in hollow charge projectiles, has theadvantage of in no way reducing the action of the perforating device onthe target. 7

The fuze of the present invention is suitable for several types ofammunition, either self-propelled or not, and particularly for thoseintended to fire on to armoured fighting vehicles. Placed at the head ornose of the projectile, it is equipped to transmit fire by wave effectto a secondary detonator located inside the explosive charge, in rear ofthe perforating hood of the hollow charge projectiles.

Since the fuze of the present invention is of very low weight, it may bemounted on a very thin jacket without the risk of deforming it byinertia on the firing of the shot, which enables the ammunition to bereduced in weight.

The fuze functions correctly even if the projectile reaches the target,armour for example, at a very high angle of incidence (which may exceed60), by virtue of the special arrangement of its head, which cuts intothe metal and thus prevents sliding off and richochets.

Operation is likewise assured on the ground or other targets affordinglittle resistance, by virtue of the small mass of the members to bedriven back and of the low resistance to shearing of the safety memberswhich it includes, particularly in the form of pins. Even if the fuzedoes not come into contact with the target, it operates by inertia whenthe projectile undergoes a certain slowing down.

The fuze of the present invention is composed of a fuze body insidewhich are disposed the firing members (striker and detonator) an elasticmember being disposed between these members, one of which is adapted toslide in said body. It is particularly characterized in that itspercussion head, integral with the body, extends in front of thefuze-carrier guide, this position being maintained by a retaining memberadapted to yield on impact against the target, said body being adaptedto slide, after yielding of said retaining memmer, inside a fuze-carrierguide mounted at the front of the projectile, and in that said head of amaterial harder than normal armour has in front sharp angles adapted topenetrate any targets, even hard ones, in such manner that it adheresand attaches itself to the point of impact, thus ensuring percussioneven at high incidences.

The harness of normal armour is that of a selected steel. Thus, for sometank parts, it is Well-known that high-quality alloy steels are used.The strength and hardness data for SAE standard steels, from MachineryHandbook, thirteenth edition, page 1574, gives a hardness for chromiumvanadium steel of 661 Rockwell C, and for high speed steel 662 RockwellC. These are maximum values for steel hardness employed in armourpractice.

According to another feature of the invention, the front part of thehard percussion head of the fuze is concave, its annular face forming anangle adapted to cut into the armour on impact. The fuze, sufficientlyslowed down on the target, is thus driven back into the fuze-carrierguide, and percussion is ensured.

According to another feature of the invention, the hard head of the fuzealso constitutes its striker, which arrangement enables the designthereof to be simplified.

According to still a further feature of the invention, the fuzecomprises a locking member preventing its body from being ejected fromthe fuze-carrier guide in the event of functioning by inertia, whileallowing the detonator to slide freely in said body, said member notintervening in the opposite direction in the event of the fuze beingdriven into the fuze-carrier guide towards the interior of theprojectile. This locking member can also fulfil its function in theevent of the body of the projectile being abruptly braked against thetarget without the fuze being touched. The locking member offers greaterresistance than the pins which might be sheared by abrupt braking inwhich case, if there were no locking member, the fuze could be ejectedfrom the fuzecarrier guide.

In one embodiment of fuze in accordance with the invention, the lockingmember consists of a ring partially engaged in a groove provided in, thefuze body and adapted to bear against an internal annular shoulder onthe fuze-carrier guide. This device has the advantage of being simpleand of offering great resistance.

An annular stop, situated in the lower part of the fuze-carrier guide,prevents it from leaving said fuze-carrier guide towards the interior ofthe projectile in the event of an unforeseen shock causing it to beprematurely driven in before being fired.

These various arrangements, proportions, dimensions and weights,independently of the technical characteristics obtained, have beenelaborated in order to make it possible to design at the same time avery light fuze, which is indispensable for equipping a projectilefurnished with a thin shell, at least in its front portion.

Moreover, since the fuze is intended for mounting in a hollow chargeprojectile, the power and the proportions of the detonator must besufficient to ensure the total destruction of said fuze in front of thehood or perforating device of said hollow charge projectile, in order toeliminate any obstacle likely to reduce the power of the projectile andthe useful effect thereof on the target.

With the object of increasing safety in case of dropping or shock, sothat the fuze may be well protected during transport and handling,whilst retaining all its sensitiveness, provision is made for adetachable hood, of a greater diameter than the collar of the shell andextending forwardly beyond the head of said fuze, t cover the fuzecompletely, said hood bearing by a wide surface upon the front portionof the shell of the projectile and fitting exactly over it.

In the event of the projectile accidentally falling on its nose from acertain height, or receiving an oblique blow, the hood will receive theblow and may be deformed, while the projecting head of the fuze willremain intact.

In order to keep the hood in place, a sheath of plastic or elasticmaterial is interposed between the outer face of the collar of the shelland the inner face of said hood, which has for this purpose asubstantially cylindrical portion and fits exactly over the sheath.

The hood is held in position by friction and can'be simply pulled off atthe moment of firing.

According to another feature of the invention, the hard head and thefuze body are integral, the striker constituted by one and the samemember being of a material different from that of said body.

In this case, the striker, the interposed elastic member (preferably acompression spring), and the detonator are mounted through the rear ofthe fuze-carrier.

It is obvious that the fuze of the invention may likewise be mounted ona thick-walled artillery projectile, in which case the fuze carrier ispreferably screwed on to the ogival head.

Further features and advantages of the invention will become apparentfrom the following description, taken in conjunction with theaccompanying drawings which illustrate diagrammatically and by way ofexample, various embodiments thereof and in which:

Fig. 1 represents, in axial section one embodiment of fuze in accordancewith the invention in the position of rest;

Figs. 2 and 3 show the fuze illustrated in Fig. 1 at the moment of itsoperation on impact, in the case of operation by driving in and in thecase of operation by inertia respectively;

Fig. 4 is a partial section showing the fuze of Fig. 1 mounted on a thinshell and provided with a protective cap;

Figs; 5, '7 and 8 illustrate modifications;

Fig. 6 shows a modification of the fuze of Fig. l. mounted on'a thickogival head.

The various figures refer to an instantaneous percussion head or nosefuze operated by being driven in or by inertia.

The fuze essentially comprises a hollow fuze body I, adapted to slideaxially in a fuze-carrier guide 2 integral with the front portion of theshell 3 of the projectile.

One of the firing memberspreferably the striker l-is rigidly mounted inthe front of the body I. The other firing member, preferably the capwhich is in the shape of a relatively large detonator 5, rests on therear portion of the body I, which comprises a base 6 preferably open asindicated at I.

A plastic or elastic member, preferably a compression spring 8, isinterposed between the striker 4 and detonator 5, this spring beingsufficiently strong to maintain the distance between these two firingmembers during transport and handling.

The striker 4 is integral with a head 9 rigidly mounted at the front ofthe body and thus constituting the percussion head of the projectile.Said head 9 is, according to the invention, made of very hard material;projecting to the front out of the fuze-carrier guide 2, it ismaintained in that position by a member capable of yielding on impact onthe target; which member comprises, for example, one or more pins I0immobilizing the body I in the fuze-carrier guide 2, which pins areshearable on impact under the. effect of shock.

Moreover, the fuze body I is provided with a locking member preventingit from being ejected from the fuze-carrier guide, said locking memberconsisting, for example, of a ring II engaged in a groove I2 in the bodyI, but projecting out of said groove, in such a manner as to form a stopagainst an internal annular shoulder I3 on the fuze-carrier guide 2.

The ring I I does not operate on impact, when the body I is driven intothe fuze-carrier guide 2 towards the interior of the projectile, butprevents any forward movement of the fuze in the fuze-carrier guide inthe event of the fuze not striking the target, whether it is thefuze-carrier guide or the body of the projectile itself which touchesthe obstacle.

An annular stop I 3a, located von'the interior portion of thefuze-carrier guide 2, prevents the fuze from leaving said fuze-carrierguide towards .fore does not ricochet or glance off on impact,

though very short, nevertheless substantially extends beyond thefuze-carrier 2 at the front and .at the rear, the whole of the fuze,including the fuze-carrier guide, having a length and a diametersubstantially only double those of the detonator 5; this arrangement ofa very short, very rigid and light unit has a favourable effect infacilitating correct operation on impact by reason of the fact thatneither warping nor jamming can take place.

Moreover, the arrangements and proportions indicated and the power ofthe detonator are combined in such a manner as to ensure the preliminaryand complete destruction of the fuze before the projection of theperforating device takes place.

To this end, the fuze is so designed that the weight thereof, includingthe detonator, is less than three times that of the detonator alone.

The striker t is disposed at a short distance from the detonator 5, inorder to ensure extremely rapid operation of the fuze on impact.

The detonator 5, which constitutes by itself the cap-carrying inertiablock, has a height equal to about twice its diameter. Its axial guidingin the body I is thus assured over a sufiicient length to avoid anyjamming in the case of an oblique impact.

In order to permit the fixing of the fuze to a thin shell, provision ismade for the latter to end at the front in a cylindrical collar whichacts as a housing for the fuze-carrier guide 2, a circular groove 22being provided on said fuzecarrier for the fixation by setting of saidcollar which, with said fuze-carrier guide, at the front end, bearsagainst a flange 23 on the fuze-carrier guide, thus being immobilisedbetween the two stops 2?. and 23. The pins [0 are covered, afterinsertion, by the collar 2| and thus cannot leave their mountings.

The mode of operation of the hereinabove described fuze is as follows:

On firing the shot, the pins It) being sufiiciently strong, the body Iremains integral with the fuze-carrier guide 2, that is to say with theprojectile itself and the parts of the fuze retain their respectivepositions.

On impact (Fig. 2), the body is abruptly stopped, while the projectilecontinues its course, and the pins IQ are sheared. The body I is thuspractically driven back into the fuze-carrier guide of the projectile,while the detonator 5, through inertia, continues its forward movementand is thrown on to the striker 4, which causes it to fire.

When impact takes place obliquely, as illustrated in Fig. 2, it will beseen that the fuze and projectile tend to pivot around the point ofimpact and to take up a position, relatively to the armour, approachingthe perpendicular and of smaller incidence, which is favourable toperforation.

It may happen that impact does not take place on the fuze and that theprojectile merely undergoes a certain slowing down, for example in theevent of the shell alone coming into contact with the target, or in theevent of said projectile engaging in the meshes of a protective netwithout its fuze touching it. In such a case, the fuze body I remainsintegral with the shell 3 of the projectile, the ring H, bearing againstthe circular shoulder l3, retains the fuze in the fuze-carrier guide.Operation is then ensured through inertia; the fuze and the fuze-carrierguide being slowed down, the detonator is thrown on to the striker 4(Fig. 3).

During storage and transport or handling, the various membersconstituting the fuze are in the position illustrated in Fig. l. Thespring 8 is sufficiently strong to prevent the detonator 5 from cominginto contact with the striker 4 in the case of an accidental fall of theprojectile on to its head. If the shock sustained by the head is suchthat the pins l0 give, the fuze is driven back inside the fuze-carrierguide 2, without there being any danger, since the inertia of thedetonator is sufficiently small for the force of the spring to sufficeto ensure the desired safety.

This safety can nevertheless be further increased by protecting the fuzeagainst all external shocks during transport and handling, by means of adetachable hood 24 (Fig. 4) of a reater diameter than the collar 2| ofthe shell 3 and extending forwardly beyond the percussion head 9. Thishood 24 bears by a wide surface 25 upon the front portion of the shell 3of thin metal, and fits exactly over it.

A sheath 26, of plastic material, is interposed between the outer faceof the cylindrical collar 2! and the inner face of the hood, which tothis end has a cylindrical portion 21. The friction of the plasticsheath of the hood 24 on the collar 2| ensures that said hood is held inplace.

Fig. 5 illustrates a modification in which the sensitiveness of the fuzeis increased, so that it can operate even against very thin targets.

On firing the shot, an arming system, a ring 32, is peripherally wedgedby inertia against the detonator 5 and compresses a spring 33, afterwhich the ring 32 and the detonator 5, rendered integral with oneanother, serve as an inertia block when the fuze functions. A very weakspring 35 keeps the detonator at a distance during the trajectory of theprojectile.

The fuze of the present invention may also be mounted in an artilleryprojectile provided with a thick ogival head 28 (Fig. 6), thefuzecarrier guide 2 being then screwed on to said ogival head.

Figs. 1, 2, 3, 5 and 6 illustrate a fuze the head 9 of which is fixed onthe body I by setting at 22. Fig. 7 illustrates a modification in whicha head 30 of greater diameter is screwed on to the body 3|, beyond whichit extends laterally.

Finally, a fuze may also be designed the head and the body of which areconstituted by the same part 35 (Fig. 8). The striker 4, the spring 8,and the detonator 5 are then installed through the rear of the body,while a ring 36 set at the rear of said body holds then in place. Thestriker 4, preferably made of a material different from that of the body35, is held in its housing by any appropriate means, for example by set-What I claim is:

1. A percussion nose fuze for a projectile, said fuze operating bydriving in and inertia, and adapted to operate upon impact even at ahigh angle of incidence in relation to the normal to the target,comprising a fuze-carrier guide, a fuze body, two firing membersdisposed inside said body, said firing members comprisinga striker and adetonating means, anelastic member interposed between said firingmembers'to keep them away from one another up to the instant of impact,said detonating means being held against sliding forward relative tosaid striker by the force of said'elastic memberduring-flight of anduntil impact of said projectile and upon impact being slid relativelyforwardly by inertia against the force of said elastic member, apercussion head secured fixedly to said striker and extending in frontof said fuze-carrier guide, retaining means between said body and saidguide for maintaining said body in its normal position until afterfiring, said body being adapted to slide within saidfuze-carrier guideuponrelease of said retaining means, said percussion head having atleast-its front peripheral edge portion made of a harder material thannormal armour, said peripheral edge portion having a sharpangledcross-section for cutting into a hard target and thereby effective tocause said head to engage the target and adhere firmly at the point ofimpact, thus ensuring percussion even at a high angle of incidence.

2. A percussion nose fuze for a projectile, said fuze operating bydriving in and inertia and adapted to operate upon impact even at a highangle of incidence in relation to the normal to the target, comprising afuze-carrier guide, a striker and a detonating means located'one infront of the other and each slidable in said fuzecarrier guide, a hollowmember slidable within the fuze-carrier guide and Supporting saiddetonating means, the striker being located within said hollow member, apercussion head fixedly connected to said striker and extending in frontof the fuze-carrier guide for contact with the target and effective uponimpact for causing said striker to be driven rearwardly relative to thefuze-carrier guide, said detonating means being slidable forwardly byinertia within and relative to said fuze-carrier guide upon impact, andsafety elements including safety means effective for preventing axialmovement of the striker upon accidental dropping beforefiring and a coilspring engaged with said hollow member and interposed between andeffective to press the striker and detonating means away from oneanother up to thetime of impact and to prevent movement of the hollowmember during flight, said percussion head having at least its frontperipheral edge portion made of a harder material than normal armour,said peripheral edge portion having a sharp-angled cross-section forcutting into a hard target and thereby effective to cause said head toengage the target .and adhere firmly at the point of impact, thusensuring percussion even at a high angle of incidence.

3. A percussion nose fuze assembly for a projectile, said fuse operatingby driving in and inertia, and adaptedto operate even at a high angle ofincidence in relation to the normal to the target, comprising; afuze-lcarrier guide; a hollow fuze body slidable relatively rearwardlyin the fuze-car'rier guide when stopped and driven in by impact upon thetarget; a retaining member effective to connect the body and thefuze-carrier guide for maintaining the body in a normal forward positionand adapted to shear upon the impact of the body on thetarget, said bodybeing adapted to slide rearward inside said fuze-carrier guide. aftershearing of said retaining member; two firing members disposed'insidesaid body and comprising a rearwardly directed striker fixed to the bodyand a detonator guided by and slidable relatively forwardly in the bodyby inertia upon impact and into detonating engagement with thestriker; acompression coil spring interposed between said firing members to keepthem away from one another up to the instant of impact of thefuze uponthe target; and a percussion head rigidly mounted at the front of andforming part of said body and in the said normalrforward position of thebody extending in front out of said fuze-carrierguide for impact uponthe target, said percussion head havinga peripheral cutting edge at thefront end with parts of thefront end being inclined inwardly andrearwardly from the periphery, and of a harder material than normalarmour for cutting into a hard target and thereby eifective to causesaid head to engage said target and adhere firmly at the point ofimpact, for ensuring percussion even at a high angle of incidence andalso upon oblique impact efiective for exertion of a force tending tocause the fuze and projectileto pivot around the point of impact towarda position of smaller incidence relative to the target.

EDGAR WILLIAM BRANDT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

